A Scientist Who Traveled the World to Study the Forest, and the Trees

Gordon Jacoby, 1934-2014

Gordon Jacoby Jr., a Columbia University researcher who hiked, flew, dove and paddled into some of the wildest corners on earth in search of trees that could reveal the planet’s workings, died on Oct. 1 at a hospital near his home in Raphine, Va. He was 80.

Jacoby was an early pioneer in the science of dendrochronology, the study of tree rings. In 1975, he co-founded the Tree-Ring Lab at Columbia’s Lamont-Doherty Earth Observatory, only the second lab of its kind in the United States.

Trekking into remote forests on every continent except Antarctica, he extended existing climate records by sampling trees near the top of the world, in northern Siberia, and near the bottom, in Tierra del Fuego, at the tip of South America. In between, his travels ranged from lowlands to high mountain ridges and the bottoms of lakes. Jacoby led the first reconstruction of Northern Hemisphere temperatures going back hundreds of years, helping to show humans were at the root of rising heat over the last century. He was also a leader in using tree rings to shed light on prehistoric droughts, earthquakes, tsunamis and landslides.

Born on Aug. 14, 1934 near Boston, and raised in the New Jersey suburb of Ridgewood, Jacoby was the youngest of three children. His father, Gordon C. Jacoby, designed buildings and bridges; his mother, Margaret Mathieson Jacoby, stayed home to care for the family. Jacoby attended a prep school in central New Jersey and spent six months at Vanderbilt University before joining the Marines, serving from 1953 to 1956. While stationed in Korea, he drove a tank that serviced other tanks during the postwar peacekeeping mission there.

Jacoby takes a handsaw to an old log in northern Canada’s Thelon River wilderness, circa 1984, as a colleague, Jobie Carlisle, looks on. (Rosanne D’Arrigo)

He returned with dragons tattooed on both arms, bent on putting his tinkering skills to use. He studied mechanical engineering at the Massachusetts Institute of Technology before transferring to Columbia to study geology. He graduated in 1962 and stayed on at Columbia for a PhD in hydrology, which he finished in 1971. During several detours out west, he stumbled across the tree-ring lab at the University of Arizona, then the nation’s only one.

In what would become a landmark study, he joined Arizona tree-ring scientist Charles Stockton on a project to reconstruct past flows of the Colorado River. In 1976, they published a 400-year history of the basin showing that the early 20th century had been unusually rainy and that policy makers had divided the river’s flows based on this abnormally wet period. Amid a continuing drought in the American West, the flawed Colorado River Compact still haunts the region today.

Working with Wallace Broecker, a leading climate scientist at Lamont-Doherty, Jacoby returned to Columbia to launch a tree-ring lab in a ramshackle house on the outskirts of the Lamont campus in Palisades, N.Y. He co-founded the lab with Edward Cook, a young dendrochronologist recruited from Arizona. “Because it was off-campus and off the beaten track, we didn’t get many visitors,” Jacoby recalled in a 1999 essay celebrating Lamont’s 50-year anniversary. “So for many years we lived a sort of wilderness existence, which perhaps is only fitting for a tree-ring lab.”

The lab’s first big achievement was a year-by-year account of Northern Hemisphere climate. Extracting pencil-thin cores from trees at the very edge of their northern limits, across Alaska and Canada, Jacoby and colleague Rosanne D’Arrigo published a 300-year climate record in the journal Climatic Change in 1989. Amid this longer context, it became clear that natural climate swings could not account for the runaway increase in warmth in recent decades.

With time, the lab extended the Northern Hemisphere record back 1,300 years, including tree-rings from Siberia, Mongolia and Norway. The lab also pioneered new methods to extract climate signals from tropical trees, whose continuous growth makes it difficult to catch annual changes in climate.

Jacoby figured out that trees at their limit for tolerating cold or drought provided the clearest signal, which led him to bushwhack to high ridges, parched lava fields and the borderland between boreal forest and tundra. With little more than a wetsuit, he dove into frigid lakes to retrieve samples of long-dead trees preserved in the low-oxygen water. Dead trees allowed the lab to extend their climate records back even further in time. “He just had this amazing intuitive sense of where to get the best climate signal in the field,” said Nicole Davi, an adjunct scientist at Lamont and former student.

Jacoby often packed a wetsuit on expeditions to retrieve old trees from the bottoms of lakes–here on Russia’s Taymyr Peninsula, in 1999. (Neil Pederson)

Jacoby was also at the frontier of using tree rings to study natural hazards. In a 1988 study in the journal Science, he linked California’s 1812 San Juan Capistrano earthquake to a series of pine trees with severed roots along the San Andreas Fault near Wrightwood. With tree rings and historic evidence, he concluded that the ruptured segment was at least 30 miles in length, longer than previously thought.

In a 1992 study in Science, Jacoby retrieved Douglas firs from the bottom of Seattle’s Lake Washington, to show that an earthquake had struck the region a thousand years earlier, triggering three landslides and a tsunami on Puget Sound. He also provided supporting evidence for an estimated magnitude 8 earthquake off the Pacific Northwest in 1700 that inundated the Washington-Oregon coastline and likely produced a tsunami that washed over Japan on Jan. 27, 1700. A repeat of the quake is considered a real possibility today.

He established collaborative working relationships in countries sometimes at diplomatic odds with the United States, training scientists in Mongolia, China and Russia. He also nurtured the talent in his own lab, which continues to produce important studies in the field. After formally retiring in 2001, he continued to furnish his colleagues with tree-ring samples from Mongolia, Alaska and New England.

In retirement, Jacoby settled into a 110-acre farm in Virginia’s Shenandoah Valley, where he raised red Bourbon turkeys and for a time, sheep. Each fall, he planted chestnuts in an attempt to grow trees resistant to the blight that decimated America’s native chestnut forests. He called the place “Druid’s View” for the trees blocking what might have been spectacular vistas of the Blue Ridge Mountain foothills.

Jacoby was a nearly lifelong bachelor, but in 2009, struck up a relationship with Rusty Lotti, then director of Lamont’s deep-sea sediment laboratory. The couple split their time between Nyack, N.Y. and Raphine, Va., with summers at Jacoby’s hand-built cabin on Alaska’s Kenai Peninsula. Engaged since 2010, they were making plans to officially tie the knot when Jacoby suffered a fatal stroke.

In addition to Lotti, Jacoby is survived by his brother, Ian Jacoby, of Newport News, Va. His sister, Margaret Jacoby Lindberg, died in 1998.